@article{oai:toyama.repo.nii.ac.jp:00015670, author = {Takahashi, Kei and Nagai, Nao and Ogura, Keisuke and Tsuneyama, Koichi and Saiki, Ikuo and Irimura, Tatsuro and Hayakawa, Yoshihiro}, issue = {7}, journal = {Cancer Science}, month = {Jul}, note = {application/pdf, Although the importance of the host tissue microenvironment in cancer progression and metastasis has been established, the spatiotemporal process establishing a cancer metastasis-prone tissue microenvironment remains unknown. In this study, we aim to understand the immunological character of a metastasis-prone microenvironment in a murine 4T1 breast tumor model, by using the activation of nuclear factor-jb (NF-jB) in cancer cells as a sensor of inflammatory status and by monitoring its activity by bioluminescence imaging. By using a 4T1 breast cancer cell line stably expressing an NF-jB ⁄ Luc2 reporter gene (4T1 NF-jB cells), we observed significantly increased bioluminescence approximately 7 days after metastasis-prone orthotopic mammary fat-pad inoculation but not ectopic s.c. inoculation of 4T1 NF-jB cells. Such in vivo NF-jB activation within the fat-pad 4T1 tumor was diminished in immune-deficient SCID or nude mice, or T celldepleted mice, suggesting the requirement of host T cell-mediated immune responses. Given the fat-pad 4T1 tumor expressed higher inflammatory mediators in a T cell-dependent mechanism compared to the s.c. tumor, our results imply the importance of the surrounding tissue microenvironment for inflaming tumors by collaborating with T cells to instigate metastatic spread of 4T1 breast cancer cells., Article, Cancer Science, 2015 Jul; 106(7): 867-74}, pages = {867--874}, title = {Mammary tissue microenvironment determines T cell-dependent breast cancer-associated inflammation}, volume = {106}, year = {2015} }